1. Field of the Invention
The present invention relates to a method of welding a stud made of magnesium or magnesium alloy to a base material made of magnesium or magnesium alloy.
2. Description of the Related Art
Material made of magnesium or magnesium alloy is extremely difficult to weld since a tough oxide layer forms on a surface thereof and the material oxidizes easily. For example, Japanese Published Patent Application No. 2002-172465 discloses a method of welding a stud on a base material. In accordance with the method, a large-capacity capacitor stores an electric charge, and the electric charge of the capacitor is rapidly discharged in a state that the stud having a projection at an end thereof is in contact with the base material. Thereby, an arc is instantaneously generated between the end of the stud and the base material, and consequently the end of the stud is welded to the base material.
However, it is difficult to weld a stud made of magnesium or magnesium alloy (hereinafter simply referred to as a stud) to a base material made of magnesium or magnesium alloy (hereinafter simply referred to as a base material) by adopting the above-mentioned stud welding method as it is originally. Therefore, it is extremely difficult to demand substantially effective joining strength of the stud according to its shape and material.